John N. Bahcall Biography

Born John Norris Bahcall, December 30, 1934, in Shreveport, LA; died of a
rare blood disorder, August 17, 2005, in New York, NY. Astrophysicist and
astronomer. Princeton astrophysicist John N. Bahcall is best known for his
work concerning the creation of the Hubble Space Telescope. Launched in
1990 and still orbiting the earth, Hubble has helped scientists solve many
of the universe's mysteries. In addition, Bahcall is credited with
unlocking answers to several other cosmological puzzles, including the
mystery of what makes the sun shine. Bahcall's research in the
1960s proved once and for all that the sun is fueled by nuclear reactions.

Bahcall was born on December 30, 1934, in Shreveport, Louisiana. He played
tennis in high school and had no interest in science. When Bahcall
enrolled at Louisiana State University, he decided to study philosophy,
figuring he might become a rabbi. A year later, Bahcall transferred to the
University of California at Berkeley, having never completed a science
class in his life. At Berkeley, science was required, so he opted for
physics. "It was the hardest thing I have ever done in my life, but
I fell in love with science," Bahcall recalled during a 2002
commencement speech, according to
Washington Post
staffer Joe Holley. "I was thrilled by the fact that by knowing
physics you could figure out how real things worked, like sunsets and
airplanes, and that after a while everyone agreed on what was the right
answer to a question." After the course, Bahcall decided to study
physics and astronomy, choosing to rely on science—not
spirituality—in his quest for greater truths.

Bahcall finished his undergraduate degree at UC Berkeley in 1956, then
earned graduate degrees in physics, including a master's in 1957
from the University of Chicago and a doctorate from Harvard University,
which he completed in 1961. Bahcall then worked as a research fellow at
Indiana University and later joined the Kellogg Radiation Laboratory at
the California Institute of Technology. While there, he worked on a series
of calculations concerning the sun. Bahcall believed that the sun was
probably powered by nuclear reactions, and he concluded that if so, the
sun should be sending subatomic particles called neutrinos toward the
earth along with its light.

He started working with astrophysicist Raymond Davis Jr. of the Brookhaven
National Laboratory and the pair began what would become a decades-long
collaboration. Together, they concocted an experiment to collect
neutrinos. They built a neutrino detector, which was really an enormous
tank filled with a chlorine-based cleaning fluid and sunk into the pit of
an abandoned South Dakota gold mine. For the most part, the neutrinos
passed through the tank undetected, just as they passed through all
other matter, including the earth. Some neutrinos, however, collided with
the chlorine atoms to create radioactive atoms. Periodically, Davis and
Bahcall counted the radioactive atoms.

In 1968 they reported their experiment to the scientific world, noting
that they had been able to capture and study neutrinos from the sun, thus
proving that the sun's light is derived from nuclear reactions. The
mystery of how the sun shines had puzzled scientists for
decades—and Bahcall's investigation settled the matter.

That same year, Bahcall joined the Institute for Advanced Study at
Princeton University. There, he continued his investigations with
neutrinos and also studied the dark matter of the universe and the
evolution of stars. By 1971, he was a full faculty member—a
professor of natural resources. He trained batches of astrophysicists,
many of whom became leaders in the field.

Bahcall spread his passion around the globe, traveling abroad to help
launch astronomy groups at Tel Aviv University and the Weizmann Institute
of Science, both in Israel. During one of these trips, he met Israeli
graduate student Neta Assaf. Bahcall asked her out more than ten times
before she accepted a date. Though Bahcall could not speak Hebrew and
Assaf was not fluent in English, their relationship flourished and they
married within a year. After relocating to the United States with her new
husband, Neta Bahcall became a cosmologist at Princeton. They hold the
distinction of being the only astronomy couple each with memberships to
the National Academy of Sciences.

By the 1970s, Bahcall had started working with Princeton astronomer Lyman
Spitzer Jr. to advocate for the development of a space telescope. Spitzer
had proposed the idea of a space telescope back in the 1940s but the
project did not seem viable until the 1970s when technology had advanced.
Bahcall and Spitzer made numerous appearances before Congress and, after
winning approval, worked on the Hubble Space Telescope's
development. It was finally launched in 1990 by the space shuttle
Discovery and put into orbit 370 miles above the earth. Since then, the
telescope has been making daily observations of space free from the
distractions imposed by the earth's atmosphere.

Speaking to the
Los Angeles Times
shortly after Bahcall's death, Caltech astronomer Maarten Schmidt
recalled Bahcall as a "tenacious" creature who would never
give up on an idea "and it really paid off with the Hubble Space
Telescope." Bahcall remained loyal to the instrument to the end.
When former National Aeronautics and Space Administration (NASA)
administrator Sean O'Keefe announced that there would be no more
shuttle missions to repair the telescope following the 2003 explosion of
the shuttle Columbia, Bahcall put up a fight. He penned editorials and
made calls on the telescope's behalf from his hospital bed as he
lay dying. Eventually, NASA agreed to reconsider.

In 2002, Raymond Davis—the man Bahcall had done his neutrino
collaboration with—earned the Nobel Prize in Physics for his
investigations into neutrinos. Davis shared the award with University of
Tokyo professor Masatoshi Koshiba, who had also worked on neutrino
detection. Many physicists believed Bahcall should have been honored as
well, but he never complained. Bahcall did receive numerous awards over
his lifetime, including NASA's Distinguished Public Service Medal
in 1992 for his work with the Hubble Space Telescope. Bahcall also
received the National Medal of Science in 1998. Over the course of his
career, Bahcall wrote more than 500 scientific papers and published five
books related to astrophysics, astronomy, and neutrinos. His writings
helped other scientists better understand the cosmos.

Bahcall died of a rare blood disorder on August 17, 2005, at New
York-Presbyterian/Weill Cornell Hospital. He was 70. Survivors include his
wife, sons Safi and Dan, his daughter, Orli, and his brother, Robert.
Sources:
Los Angeles Times,
August 20, 2005, p. B16;
New York Times,
August 19, 2005, p. C14;
Times
(London, England), September 1, 2005, p. 68;
Washington Post,
August 20, 2005, p. B6.

—
Lisa
Frick

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